i) Field of the Present Invention
The present invention relates generally to metal making apparatus, and more particularly to apparatus for opening and closing a taphole of a metallurgical furnace.
ii) Description of the Prior Art
In the making of molten metal in a metallurgical furnace, such as pig-iron in a blast furnace, the molten metal usually is tapped from the furnace through one or more tapholes. While the furnace is in the operation of metal making the taphole(s) should be closed.
A usual way of closing the taphole consists in filling it with refractory clay after each tapping operation. For that purpose plugging machines have been developed which are generally known and used in the art of iron making. In its servicing position such a plugging machine is moved in front of the taphole to be closed and thereupon injects refractory clay of a suitable composition under pressure into the taphole until it is closed, whereupon the plugging machine is moved away into a parked position.
Also a usual way of opening the taphole consists of drilling a hole through the refractory clay previously injected by the plugging machine. Suitable drilling machines are generally known and used in the art of iron making. In its servicing position the drilling machine is moved in front of the taphole to be drilled. After drilling the drilling machine is moved away into a parked position.
According to the known art the drilling machine and the plugging machine are separately floor mounted, either both on one side or on both sides sideways in front of the taphole.
In both cases, large areas of the cast house floor are required to accommodate the necessary swing paths of the drilling and plugging machines.
As mechanisation of the furnace operation is becoming increasingly evident, cast house floor is at a premium. In that situation the known apparatus is at a disadvantage, since the swing path areas of the drilling and plugging machines occupy too much of the available space. This holds especially for existing blast furnace plants where additional space is required in the taphole area for modernizing the furnaces by adding for instance fume extraction equipment, tilting runners, iron trough cover removal structures etc.